Zidovudine: Uses, Dosage, and Overdose

What Is Zidovudine?

Zidovudine, also called Azidothymidine (AZT), is one of the earliest and most well-known medicines used to treat HIV. It works in a very smart way by copying the shape of a natural substance in our body called thymidine, which is a building block of DNA.

To understand how AZT works, think of how HIV multiplies inside the body. HIV carries its genetic information as RNA, not DNA. To infect a human cell and take control, the virus first needs to convert its RNA into DNA. It does this using a special enzyme called reverse transcriptase, almost like a tiny machine that helps the virus rewrite its genetic code.

Here’s where AZT comes in:

• When HIV tries to make new DNA, AZT sneaks in because it looks so similar to thymidine.

• Once AZT gets inserted into the growing chain of viral DNA, the process stops suddenly, because AZT is a “faulty” building block.

• This means HIV cannot finish making its DNA.

• And without this full DNA strand, the virus cannot insert itself into the human cell’s genetic material.

• As a result, HIV cannot multiply as easily, and the infection slows down.

In simple terms, AZT interrupts HIV’s copying process, making it harder for the virus to grow and spread in the body. This helps protect the immune system and slows the progression of HIV.

What Are the Uses of Zidovudine?

Prevention of HIV (Post-Exposure Prophylaxis – PEP) Zidovudine for HIV PEP is often used along with other HIV medicines like Lamivudine to prevent infection after someone has been exposed to HIV. This is called post-exposure prophylaxis (PEP).

• PEP is usually needed when a person accidentally comes into contact with HIV-infected blood, body fluids, or tissues.

• It is especially common among healthcare workers, such as nurses or laboratory technicians, who may experience needle-stick injuries.

• Zidovudine is also given to pregnant women with HIV to reduce the risk of passing the virus to their baby during pregnancy, labor, or delivery.

Treatment of HIV Infection

Zidovudine is used as part of a combination treatment for people who already have HIV.

• It is usually taken twice a day along with other antiretroviral medications.

• Using multiple drugs together helps control the virus more effectively and prevents it from becoming resistant.

• This treatment approach is known as highly active antiretroviral therapy (HAART), which is the standard method to keep HIV under control and protect the immune system.

Antibacterial action besides HIV treatment:

Zidovudine also shows action against certain bacteria.

• When combined with other antibacterial medicines, it may help fight multidrug-resistant Gram-negative bacteria, which are harder to treat with regular antibiotics.

• This makes Zidovudine useful in specific, difficult-to-treat infections.

What Is the Normal Dosing Regimen for Zidovudine?

Oral Dose for HIV Treatment

Zidovudine is used along with other antiviral medicines to treat HIV infection.

Adults:

• 300 mg twice a day (with other HIV medicines).

Infants and children:

• The dose depends on body weight.

• Weighing more than 30 kg: 60 mg per day (given in divided doses).

• Weight less than 30 kg (down to 9 kg): 18 mg per kg per day (in divided doses).

• Weight less than 9 kg (down to 4 kg): 24 mg per kg per day (in divided doses).

Oral Dose for Preventing HIV Transmission in Pregnancy

Zidovudine is also used to lower the risk of a pregnant woman passing HIV to her baby.

Pregnant women:

• It usually starts after 14 weeks of pregnancy.

• Continued until childbirth.

• 100 mg taken five times a day.

Newborn infants:

• The dose depends on the baby’s weight.

• 2 mg per kg of body weight every six hours.

• Started 12 hours after birth.

• Continued until the baby is six weeks old.

What Are the Special Precautions With Zidovudine?

The precautions for taking Zidovudine are as follows:

• The pregnant and breastfeeding mother should inform the doctor before taking Zidovudine.

• Zidovudine should be stored at room temperature, away from the light and moisture. The drug should be kept away from the children.

• Take precautions to avoid infections, such as washing hands regularly and avoiding close contact with sick people.

What Are the Side Effects of Using Zidovudine?

Side effects of Zidovudine depend on the body's reaction to the drug. It includes the following:

• Headache.

• Trouble sleeping.

• Constipation.

• Rash.

• Joint pain.

• Itching.

• Heartburn.

• Peeling of the skin.

• Muscle weakness.

• Weight loss.

• Stomach cramps.

• Blistering of skin.

• Hives (itchy, raised red bumps).

• Swelling of the eyes, tongue, and face.

What Is Zidovudine Overdose?

The Zidovudine dosage depends on the patient's age and the severity of the infection. For normal adults, 300 milligrams are given twice a day (a total of 600 milligrams per day).

Zidovudine doses must be monitored regularly to avoid adverse effects due to overdose. Studies have shown an increased risk of developing neurotoxicity and hematological toxicity with Zidovudine overdose.

The adverse effects and toxic reactions associated with Zidovudine overdose include the following:

• At high doses, Zidovudine may inhibit the DNA polymerase enzyme used by normal human cells for cell division and cause cell damage. They can also act on mitochondrial DNA polymerase enzymes and cause damage to skeletal and cardiac muscles (myositis).

• Anemia is often associated with Zidovudine overdose. Reduced red blood cells in the body cause reduced oxygen availability to tissues and organs. This can result in fatigue, dizziness, headache, skin pallor, shortness of breath, and a fast heart rate.

• Neutropenia (low neutrophil count) is also observed with Zidovudine overdose. There will be a very low count of neutrophils (white blood cells) in the body, which will cause increased susceptibility to infection.

• Elevations of bilirubin levels are observed with Zidovudine overdose. Bilirubin is a yellow-orange pigment produced in the body as a result of red blood cell breakdown.

• Neurotoxicity is an important effect associated with Zidovudine overdose. Alterations in protein and lipid metabolism, oxidative stress, and mitochondrial damage will cause neurotoxicity. Zidovudine overdose will induce cellular stress and neuronal damage. Disrupted nerve cell activity will cause seizures.

• Gastrointestinal irritations are common after a Zidovudine overdose. In addition, there will be gastrointestinal symptoms like cramps, diarrhea, and loss of appetite during a Zidovudine overdose.

• Myopathy induced by Zidovudine overdose will cause muscle fatigue, wasting, and weakness. Patients taking Zidovudine for a long time are often associated with muscular diseases.

• Zidovudine overdose may cause life-threatening liver damage and result in a life-threatening condition called lactic acidosis (too much lactic acid in the blood).

• Headache and severe nausea are seen in patients due to increased levels of Zidovudine in the body.

What Are the Dietary Instructions While Taking Zidovudine?

The dietary instructions while taking Zidovudine are as follows:

• The condition can interact with other drugs, such as antiretroviral medications, antibiotics, and Methadone.

• Drink plenty of fluids.

• It can be taken with food or without food. Taking it with food can reduce stomach upset.

• Limit alcohol consumption because alcohol can increase the risk of liver damage.

• Take a balanced diet rich in fruits, vegetables, and whole grains.

• Avoid high-fat and greasy food.

Conclusion:

Zidovudine (AZT) is a medicine used along with other antiviral drugs to help prevent and control HIV infection. It works by stopping the virus from multiplying inside the body.

Doctors may also use Zidovudine to prevent HIV from passing from a pregnant woman to her baby and to protect people after accidental exposure to HIV-infected blood or body fluids.

The dose of Zidovudine depends on a person’s body weight, age, and health condition. If you want guidance on proper dosing, safety, or HIV prevention options, consult and speak to an HIV doctor.

Key Takeaway

• Zidovudine (HIV medicine) helps control HIV by stopping the virus from multiplying.

• It is used for treatment, preventing mother-to-child transmission, and after accidental HIV exposure.

• Doses vary by weight and health, so regular doctor monitoring is essential to avoid side effects.